文摘
An easily obtainable thiol-selective labeling reagent [<sup>18sup>F]FBSEM (N-[2-(4-[<sup>18sup>F]fluoro-N-methylbenzenesulfonamido)ethyl]maleimide) was developed. The advantage of the design is that the precursor and [<sup>18sup>F]FBSEM have the same backbone and backbone construction is not required; in contrast, known thiol-specific labeling reagents do require backbone construction, and this is thought to be the cause of their complicated synthesis. [<sup>18sup>F]FBSEM was successfully obtained in higher yield (25%) and in a simpler way (two fluorination and deprotection steps in 65 min) than the widely used [<sup>18sup>F]FBEM (N-[2-(4-[<sup>18sup>F]fluorobenzamide)ethyl]maleimide). The labeling efficacy of [<sup>18sup>F]FBSEM was confirmed by conjugation with glutathione. [<sup>18sup>F]FBSEM is a promising labeling agent for proteins.